A regional ministry of education has waded into Spain's abortion debate by promoting an anti-abortion film competition for students.

The contest, posted on the website for the ministry of education in Aragon, invites students between the ages of 14 and 18 to submit short films that "demonstrate the value of life, starting at conception, for every single human".

Winners stand to earn up to €500 (£410) in prize money. Films will be judged on the extent to which they "defend the life of the unborn" and "shed a positive light on women's decision, in the face of an unplanned pregnancy, to opt for life".

The competition comes a month after the Spanish government put forward legislation that aims to sharply limit women's access to abortion across the country. In some of the most restrictive abortion legislation enacted in Europe, terminations will only be allowed in the case of rape or when there is a serious mental or physical health risk to the mother. Exceptions would be allowed for special cases, such as when foetal deformities could endanger a child's life.

The Aragonese ministry of education has sought to distance itself from the film competition, saying it belonged to two independent anti-abortion associations. It added that the competition was included on the ministry's website to promote audiovisual activities among students in the region. "We only ever exclude content that is illegal," a spokesperson for the ministry told El Pais. The ministry said it had no plans to pull the ad.

The Platform for the Defence of Public Schools in Zaragoza, which groups together students, teachers and administrative staff, urged the ministry to take down what it called "propaganda". In a statement, it said: "The department has overstepped its mandate by trying to transfer its own values to its students." It reminded the ministry that "education has more to do with plurality and scientific knowledge than moral and religious doctrines".

Mar Grandal from Católicas por el Derecho a Decidir (Catholics for the Right to Decide) said the fundamental idea behind the contest was illogical. "They suggest to women that they aren't capable of making decisions regarding their own bodies, yet they say a child of 14 years knows enough about the issue to make a video?" she said.

The proposed law has sparked protests across Spain and France and provoked a backlash against the governing People's party. A recent Metroscopia poll showed Spain's Socialist party would earn 33.5% of the vote, against 32% for the People's party, if elections were held now – the drop in support, said pollsters, was partly due to the move to restrict abortion.

The People's party government has repeatedly defended the legislation, saying that it was an election promise that must be fulfilled. The bill is expected to be passed by parliament in late spring.